&nbspReflection: Routines and Procedures The Life Cycle of Sea Squirts and Jellyfish - Section 4: Explain

If students are unfamiliar with inside-outside lines, I count out half the class and walk them in a line to a space along the wall. Then they hold hands loosely, spread out, release hands, and face the center of the room. Then I send other students one at a time and tell them who to stand with. Those students, facing the already placed children, are the inside line. The inside line rotates after each partner has had time to share their observations. (This takes about 1 1/2 minutes). Then I have 3 students from the inside line peel off and follow me (theatrically) around the room, where they join the other end of the line. The remaining inside-line children all shuffle down 3 spots. Then they repeat the activity.

Big Idea:
Even the most unusual and unexpected living things have certain life processes in common with us.

At the start of this lesson, I ask students this question: What do you know about animal life cycles? What do animals look like when they are born? How do they grow and change?

Then the students briefly share their ideas with neighbors and I walk around and listen to what they have to say.

Next I tell them that today we will look at the life cycle of a lesser-known animal group. At the end of the lesson they will be able to state what the life cycles of these animals have in common with all living things.

I show them this short video, Lesser Known Animal, to get them interested in these unusual ocean creatures.

Resources (1)

Resources

I show students a short visual presentation I created, The Life Cycle of a Sea Squirt. We briefly discuss the different stages. For students that are curious about the similarity between tadpoles and the larval form of sea squirts, you can point out that in their larval form, sea squirts have the most basic parts of a backbone system, though this quickly goes away. So, while the adult form is very clearly a boneless animal, technically, they are not invertebrates!

I ask students to write down at least 2 observations about the sea squirt life cycle. If they need focus, I ask them, "Are they born? Do they grow and change? Do they have an adult form? Do they die?"

Next, I project this excellent jellyfish life cycle animation from the New England Aquarium in Boston, Massachusetts. We read through it together and only after we have clearly read the information do I allow a student to come up and run the mouse for the class. After she has correctly chosen the first stage of the jellyfish life cycle, students discuss their observations with a partner for 1 minute before I call on a second student to come up. An alternative is to run the animation myself the first time through. I have found that with a text rich animation such as this it is best not to let students proceed through it independently until I have clearly set the expectation that they should read and ask themselves questions or make observations about each stage. Otherwise they will just "click through". After the jellyfish animation is complete, I again ask students to make a few observations/notes/questions about what they observed.